JP2001084542A - Magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply an MR head and an induction type magnetic head to a helical scanning system and an azimuth recording system and to narrow the track width without lowering the reproducing output. SOLUTION: When a magnetic tape obliquely travels to the outer periphery of a rotary drum 10 and the rotary drum 10 is rotated in the same direction, at the time of recording, a recording head 1a performs recording by tracing the odd-numbered track of the tape at an azimuth angle = +α and also the recording head 2a performs recording by tracing the even-numbered track of the tape at the azimuth angle = -α. At the time of reproduction, a reproducing MR head 1b performs the reproduction by tracing the odd-numbered track of the tape at the azimuth angle = +α and also the reproducing MR head 2b performs the reproduction by tracing the even-numbered track of the tape at the azimuth angle = -α. Further, a VCM 4 is controlled so as to make the reproducing MR heads 1b and 2b accurately trace a recording track.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus for recording / reproducing information signals on / from a magnetic tape by a rotating magnetic head.

[0002]

2. Description of the Related Art A video tape recorder (VTR) is a typical example of this type of magnetic recording / reproducing apparatus. The function has been greatly improved. Further, as another related technology that has been dramatically advanced, there is a method of increasing the recording density and reducing the track width (narrowing the track) as one method of increasing the recording density. Specifically, the track is narrowed to 19 μm in the VHS standard E mode with a drum diameter of 62 mm, and to 10 μm in the DVC standard with a drum diameter of 21.7 mm, and the amount of recorded data is dramatically increased with the advance of digital broadcasting in the future. Therefore, it is desired to further increase the recording density of a VTR that records broadcast data.

In order to increase the recording density of a VTR, it is effective to reduce the track width (narrow the track).
The narrowing of the track causes the following problems. (1) The reproduction output decreases. (2) When the recorded VTR and the reproduced VTR are different,
That is, when so-called “compatible playback” is performed, the track pattern at the time of recording does not match the head trace locus at the time of playback.

FIG. 5 shows a magnetic tape T for performing compatible reproduction.
Recording track pattern 1 by VTR (deck) A above
1 is indicated by a dotted line, and the locus 12 of the reproducing head of the VTR (deck) B is indicated by a solid line. In the deck A, the recording track pattern 11 is not a straight line but has a slightly convex downward characteristic.
When this is reproduced by the reproducing head of the deck B having a slightly convex upward characteristic, only the area indicated by oblique lines can be reproduced, and the reproduction output is reduced. In this case, it is difficult for the reproducing head to completely trace the recording track 11 even if the so-called tracking is performed, in which the phase of the drum rotation is shifted from the position in the longitudinal direction of the tape T. Further, depending on conditions such as a narrower track, a thinner tape T, a temperature, and the like, even if the tape T recorded by the deck A is reproduced by the same deck A, that is, so-called "self-recording reproduction" is performed. Also cannot be completely traced.

A hard disk drive (HDD), which is another example of a magnetic recording / reproducing apparatus, has recently been developed as a high-sensitivity magnetic head using a magneto-resistance (MR).
ffect: magnetoresistive effect)
The recording density has been dramatically improved. However, MR
Since the head is a read-only head having no recording function, the HDD uses both an MR head and an inductive (inductive) head as shown in, for example, Japanese Patent Application Laid-Open No. 10-293978.

[0006] Also, as another advanced technology of VTR,
As a method for running a magnetic tape at a predetermined running speed during reproduction and for making a rotating head coincide with a recording trace of an information signal recorded on the tape, as shown in FIGS. (Also called "head")
To control the rotation trajectory of the rotating drum 1
A head driving device (actuator) that drives in the 0 axis direction is known. 6 and 7 respectively show a piezoelectric bimorph 7 and a voice coil as the actuator.
The motor (VCM) 4 is shown. Note that the latter VCM
No. 4 is disclosed in, for example, Japanese Utility Model Laid-Open No. 4-12101.

[0007]

By the way, the above-mentioned Japanese Patent Application Laid-Open No. 10-293978 discloses a configuration using both an MR head and an inductive head in addition to an HDD.
It is described that the present invention can be applied to a VTR and the like. However, the recording medium of the HDD is a rotating disk, and its track is spiral or concentric,
Therefore, the head of the HDD only needs to move in the radial direction of the disk, and its structure is simple. However, since the recording medium of the VTR is a tape and its tracks are of the helical scan type and the azimuth recording type, the MR head Cannot be easily applied to a VTR or the like.

Therefore, the present invention has been made in view of the above problems, and
R head and induction type magnetic head can be applied to helical scan method and azimuth recording method,
It is an object of the present invention to provide a magnetic recording / reproducing apparatus capable of narrowing a track width without reducing a reproduction output.

[0009]

In order to achieve the above object, the present invention provides at least two systems of MR heads having different azimuth angles and an induction type magnetic head.
An actuator for driving the head is provided.

That is, according to the present invention, a rotating drum,
A first inductive magnetic head mounted on the rotating drum so as to trace odd tracks of the magnetic tape at a predetermined azimuth angle during recording, and a first inductive magnetic head mounted on even tracks of the magnetic tape during recording A second inductive magnetic head attached to the rotating drum so as to trace at an azimuth angle opposite to the above, and an odd track of the magnetic tape during reproduction is traced at the same azimuth angle as the first inductive magnetic head. A first MR head attached to the rotating drum and a second MR head attached to the rotating drum so that even tracks of the magnetic tape are traced at the same azimuth angle as the second inductive magnetic head during reproduction. 2 MR heads and the first,
An actuator for driving the second MR head to trace the odd and even tracks is provided.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing a first embodiment of a rotating drum of a magnetic recording / reproducing apparatus according to the present invention.

FIG. 1A shows a side surface of the rotating drum 10 and FIG. 1B shows a lower surface of the rotating drum 10.
Although not shown, a magnetic tape (not shown) slides obliquely on the outer periphery of the rotary drum 10, and the magnetic tape is helically scanned. On the outer peripheral surface of the rotating drum 10, an inductive recording head 1a having an azimuth angle of + α for tracing and recording an odd track of the tape for recording is fixed via a support 3-1. Considering these recording heads 1a and 1
An inductive recording head 2a having an azimuth angle of -α for tracing and recording an even track of the tape at a position facing 80 ° is fixed via a support 3-2.

Further, on the outer peripheral surface of the rotary drum 10, a reproducing MR head 1b having an azimuth angle = + α for tracing and reproducing an odd track of the tape is arranged, and a position facing the reproducing MR head 1b by 180 °. A reproduction MR head 2b with an azimuth angle of -α for tracing and reproducing even tracks of the tape is disposed in the. These four heads 1a, 2a, 1b, 2b are arranged at an angle of 90 °. The reproducing MR heads 1b, 2b are mounted movably in the axial direction of the rotating drum 10 (perpendicular to the paper) by voice coil motors (VCM) 4-1 and 4-2, respectively. Heads 1a, 2a, 1
b, 2b and the device side are transmitted by a rotary transformer (not shown), while the VCM (4-1, 4-
Signal transmission between 2) and the device side is performed via a slip ring 5 provided on a shaft of a rotary drum 10 and a brush 6 fixed to the device side, as shown in FIG. The azimuth angle of each head may be set so that the odd track and the even track have opposite azimuths.

According to such a configuration, when the magnetic tape runs obliquely to the outer periphery of the rotary drum 10 and the rotary drum 10 rotates in the same direction, the recording head 1a at recording has an azimuth angle of + α and The recording is performed by tracing the odd track, and the recording head 2a performs the recording by tracing the even track of the tape at the azimuth angle = −α. At the time of reproduction, the reproduction MR head 1b traces and reproduces an odd track of the tape at an azimuth angle of + α, and the reproduction MR head 2b traces and reproduces an even track of the tape at an azimuth angle of -α. Further, as will be described in detail later, the reproducing MR head 1
b and 2b so that they accurately trace the recording track.
CM4 is controlled. When recording and reproducing digital signals, the induction recording heads 1a and 2a and the reproduction MR
The heads 1b and 2b do not necessarily have to be opposed by 180 °, and may be mounted so that the heights match the odd and even tracks.

Next, a second embodiment will be described with reference to FIG. In the second embodiment, the read MR heads 1b and 2b are attached by a piezoelectric bimorph 7 instead of the VCM 4 so as to be movable in the axial direction of the rotating drum 10 (the direction perpendicular to the paper). The recording head 1a and the recording head 2a and the reproducing MR head 1b and the reproducing MR head 2b are arranged so as to face each other by 180 °. However, the recording head 1a and the reproducing MR head 1b and the recording head 2a and the reproducing MR head are arranged. 2b are arranged at an angle closer than 90 °. When it is not necessary to consider the dynamic balance of the rotating drum 10, it is not necessary to arrange the recording head 1a and the recording head 2a and the reproducing MR head 1b and the reproducing MR head 2b so as to face each other by 180 °.

Next, a third embodiment will be described with reference to FIG. In the third embodiment, the azimuth angle =
The recording head 1a of + α and the recording head 2a of azimuth angle = −α are supported by one support 3 and fixed to the rotating drum 10. Further, a reproduction MR head 1b with an azimuth angle of + α and a reproduction MR head 2b with an azimuth angle of −α are mounted movably in the axial direction of the rotary drum 10 via one VCM 4. Note that these heads are known as double azimuth heads in which a magnetic gap is attached to one base in close proximity. At this time, the read MR head 1b is
The reproducing MR head 2b is disposed at a position facing the recording head 2a by 180 ° with respect to the recording head 2a.

Next, the overall configuration of the magnetic recording / reproducing apparatus will be described with reference to FIG. The signal recording / reproducing circuit 101
At the time of recording, input signals such as an image signal and an audio signal are gated in units of one field (= 1 track unit) by a gate signal and output to the switch SW. Switch S
The switching timing of W is determined based on a drum FF (flip-flop) signal synchronized with the rotation of the rotating drum 10 and the drum rotation control circuit 103 and the system controller 10.
Performed by 0. The switch SW outputs an input signal of the odd field to the print head 1a and outputs an input signal of the even field to the print head 2a. Play M when playing
Odd-field and even-field signals reproduced by the R heads 1b and 2b are output via the switch SW and the signal recording / reproducing circuit 101, respectively.

The rotating drum 10 has a drum rotation control circuit 10
3 performs speed control and phase control. At the time of recording, a CTL signal generated by a CTL (control) signal recording / reproducing circuit 105 is sent to a CTL head 106 and recorded in the tape running direction with respect to the edge of the tape.
During playback, the CTL signal recorded on this tape is CTL
Reproduced by the head 106, the tracking control is performed by the capstan control circuit 107 controlling the capstan motor 108 based on the CTL signal.

The system controller 100 generates a tracking signal for the MR head based on the reproduction signal, and the head drive control circuit 102 causes the reproduction MR heads 1b and 2b to accurately trace the recording track based on the tracking signal. The VCM 4 or the piezoelectric bimorph 7 is controlled so that As a method of generating a tracking signal using a reproduced signal, a pilot signal is recorded in advance on a part of a track at the time of recording and reproduced, or a reproduced FM envelope is detected, and these are used. Methods are known.

[0020]

As described above, according to the present invention, at least two systems of M having different azimuth angles are provided on the rotating drum.
Since the R head and the induction type magnetic head are provided and the actuator for driving the MR head is provided, the MR head and the induction type magnetic head can be applied to the helical scan method and the azimuth recording method, and the reproduction output decreases. And the track width can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a rotating drum of a magnetic recording / reproducing apparatus according to the present invention.

FIG. 2 is a configuration diagram illustrating a rotating drum of a magnetic recording and reproducing apparatus according to a second embodiment.

FIG. 3 is a configuration diagram illustrating a rotating drum of a magnetic recording and reproducing apparatus according to a third embodiment.

FIG. 4 is a block diagram showing a magnetic recording / reproducing apparatus according to the present invention.

FIG. 5 is an explanatory diagram showing a recording track pattern and a trace locus of a reproducing head.

FIG. 6 is a configuration diagram illustrating a piezoelectric bimorph as an example of an actuator.

FIG. 7 is a configuration diagram showing a voice coil motor (VCM) as another example of the actuator.

[Explanation of symbols]

1a Recording head (first inductive magnetic head) 2a Recording head (second inductive magnetic head) 1b Reproduced MR head (first MR head) 2b Reproduced MR head (second MR head) 4 Voice coil・ Motor (VCM: actuator) 7 Piezoelectric bimorph (actuator) 10 Rotary drum

Claims (3)

[Claims] A rotating drum; a first inductive magnetic head attached to the rotating drum so as to trace an odd track of the magnetic tape at a predetermined azimuth angle during recording; and an even track of the magnetic tape during recording. A second inductive magnetic head attached to the rotating drum so as to trace the magnetic tape at an azimuth angle opposite to that of the first inductive magnetic head; A first MR head attached to the rotating drum so as to trace at the same azimuth angle as the magnetic head, and an even track of the magnetic tape during reproduction is traced at the same azimuth angle as the second inductive magnetic head. A second MR head attached to the rotary drum, and the first and second MR heads are odd and even tracks. An actuator for driving to trace the magnetic recording and reproducing apparatus having. 2. The first induction type magnetic head and the second induction type magnetic head.
2. The inductive magnetic head of claim 1, wherein the first MR head and the second MR head are attached to the rotary drum so as to face each other by 180 degrees.
The magnetic recording and reproducing apparatus according to claim 1. 3. The first and second induction type magnetic heads are constituted by double azimuth heads attached to the rotary drum via a common support, and the first and second M magnetic heads are provided.
2. The magnetic recording / reproducing apparatus according to claim 1, wherein the R head comprises a double azimuth head attached to the rotary drum via a common actuator.